Mineral material, such as rock, can be extracted from the ground for crushing either by explosions or excavation. The rock may also be natural stone and gravel, or construction waste. Both mobile crushers and stationary crushing applications are used for crushing. The material to be crushed is fed with an excavator or wheel loader to a feed hopper of a crusher or crushing plant, from where the material to be crushed may fall into the throat of the crusher, or a feeder transfers the rock material towards the crusher. The mineral material to be crushed may also be recyclable material, such as concrete, bricks, or asphalt.
Jaw crushers are suitable for, for example, rough crushing at quarries or crushing of construction material. According to the operating principle of the jaw crusher, crushing takes place against jaws, termed fixed and moving jaw.
In a known jaw crusher, a pendulum, or the moving jaw, is supported at its upper end by side plates of the jaw crusher's frame through an eccentric. A rear part of the jaw crusher's frame is fastened between the side plates. Below the eccentric, the pendulum is supported by the rear part of the frame through a toggle plate. The moving jaw is moved back and forth against the fixed jaw located at a front end of the jaw crusher and fastened to the side plates of the frame. Replaceable wear parts are fastened to the fixed and moving jaw.
The wear part is usually fastened to the jaw with a screw positioned through the jaw, tightened from a side of the jaw opposite to the fastening location of the wear part.
One way is to use a screw with threads at both ends, a first end of which is supported by the jaw on a first side of the jaw through a wedge, for example, and on a second side of the jaw, a spring and a nut are placed on the screw, with which the wear part is tightened under spring loading. Tightening the spring is difficult in the cramped space behind the jaw of the crusher. Tightening requires great forces and large tools that are difficult to move in the cramped space. Tightening is slow, because it is only possible to tighten the nut a small amount at a time with a large tool. The wear part settles in its place at the start of crushing and during it, whereby the fastening of the screw becomes loosened, and the nut has to be tightened during use. Tightening interrupts the process.
The purpose of the invention is to avoid or mitigate problems related to prior art and/or offer new technical alternatives.